The invention is concerned with power tools, particularly but not exclusively, with power tools which are relatively lightweight and suitable for use by the general public.
In my British Patent No. 2219958 there is described a portable power tool which comprises a housing and a drive means for operating a range of interchangeable tool bits such as scrapers and chisels or even tool bits which perform the function of a small spade in breaking up soil. All these power tools provide the user with the advantages of a linear path for the powered stroke of the bit, without a component of rotary motion. This is achieved by provided a cylinder cam mounted for rotation with an output shaft and provided with a circumferential sinusoidal cam track in which run cam followers associated with the drive shaft, which is captive against rotation. Tools made in accordance with the invention described in that specification are remarkably efficient in use as small hand-held tools, but if the intended purpose of the tool requires a greater cam throw range and/or a larger cam cylinder for smoothing action, the shaft portion carrying the cam followers is also enlarged making the components too cumbersome for ease of use and incorporation into a reasonably sized housing.